Stair traversing wheel chair mechanism



Jan. 3, 1967 H. w. ADDISON, JR

STAIR TRAVERSING WHEEL CHAIR MECHANISM Original Filed Dec. 2'7, 1962 5 Sheets-Sheet 2 1967 H. w. ADDISON, JR 3,

STAIR TRAVERSING WHEEL CHAIR MECHANISM Original Filed Dec. 2'7. 1962 5 Sheets-Sheet 5 M X a 8 N w w k; l\ Q INVENTOR. L j/APP/ WADD/50A/ JP.

H. W. ADDISON, JR

STAIR TRAVERSING WHEEL CHAIR MECHANISM Jan. 3, 1967 5 Sheets-Sheet 4 Original Filed Dec.

FIE 15 FIE 12 INVENTOR. HAPPY WApp/soxv Me Jan. 3, 1967 w. ADDISON, JR 3,295,858

STAIR TRAVERSING WHEEL CHAIR MECHANISM Original Filed Dec. 2'7, 1962 5 Sheets-Sheet 5 Q N 1- v n o m 6 y INVENTOR. HARRV M 4019/50 f2.

United States Patent Office 3,295,858 Patented Jan. 3, 1967 6 Claims. (Cl. 280-53) In general, this invention relates to wheel-chairs that can be operated in ordinary ways and that can be operated on stairs.

A main object, of the invention, is to provide a self contained wheel-chair for enabling the occupant thereof to traverse flights of stairs, independent of outside mechanical or manual assistance.

Another object is to provide a wheel-chair with an adjustable length wheel base that may be lengthened to increase stability for traversing rough ground, street curbs, single step rises, etc. Lengthening the wheel base may also be used to provide a semi-reclined restful position.

My invention for entering or leaving either the top or bottom of a flight of stairs may be used in combination with any suitable wheel-chair means for ascending or descending stairs.

It is a further object of my invention to provide a wheel chair capable of ascending and descending stair flights which has for its primary climbing apparatus a hydraulic piston system which is operated by the user of the chair such that he may propel himself either up or down stairs through his own force.

Throughout the accompanying drawings, like reference characters refer to the same or similar parts throughout, with no distinction being made between right or left hand parts on opposite sides of the Wheel-chair.

FIG. 1 is a side elevation of a chair embodying the concepts of applicants invention and being shown in stair climbing position;

FIG. 2 is a top plan view of FIG. 1;

FIG. 3 is a schematic illustration of the chair with the solid line illustrating the normal running position and the dotted illustration showing a lengthened wheel base for the chair;

FIG. 4 is a schematic illustration showing the chair in ascending or descending position on a step;

FIG. 5 is a view similar to FIG. 4 illustrating either a prior or subsequent position of the chair depending on whether the chair is ascending or descending a stair flight;

FIG. 6 is a schematic illustration of the chair entering or leaving the bottom of a flight of stairs;

FIG. 7 is a schematic illustration similar to that of FIG. 6 showing the chair in a position either prior or subsequent to the position shown in FIG. 6;

FIG. 8 is a schematic illustration wherein the wheel chair is about to be lifted on to the first step of a flight of stairs;

FIG. 9 is a schematic illustration illustrating the position of the chair at the top of a flight of stairs;

FIG. 10 is again a schematic illustration showing the operation of the chair at the top of a stair flight;

FIG. 11 is a schematic illustration showing the chair as it would appear either entering or leaving the top of a flight of stairs;

FIG. 12 is a vertical section through one of the hydraulic lifting units;

FIG. 13 is a transverse section taken along line 1313 of FIG. 12;

FIG. 14 is an enlarged view of a portion of FIG. 1 particularly illustrating a braking device;

FIG. 15 is a vertical section taken from the front of FIG. 14.

FIGURE 1 is a side view and FIGURE 2 is a top view of the same wheel-chair. Number 1 is the main frame and the chair seat 2, the chair back 3, the chair arm rests 4, the arm rest supports 5, and the seat supports 6 are hinge connected to the frame 1 so they can be folded for transporting. The foot rest 7 is also connected to and supported by the main frame 1.

Number 8 is a bar fixed in a convenient place to be used as a fulcrum for correcting misalignment, between the wheel-chair and stairs, with a lever such as cane or crutch.

Number 9 is a transverse shaft journaled in bearings 10 that are mounted on the main frame 1, above and behind the seat 2. The case 11 contains gears for rotating the shaft 9 in either direction and for securing the shaft 9 at any point of rotation. The said gears are turned with the crank 12 that is ratchet mounted on the gear driving shaft 13. The bearing 14 maintains the shaft 13 and the gear case 11 in a fixed position relative to the main frame 1. Rear wheel supporting stems 15 are firmly mounted at each end of the transverse shaft 9. Rear caster wheels 16 are attached to the outer end of the stems 15 and may be provided with locks 17 to prevent castering.

It will now be clear that the stems 15 and wheels 16 can be revolved through 360 in planes that are parallel to each other and that are parallel with the sides of the wheel-chair. By providing 360 revolutions for the wheels 16 and stems 15 it is possible to lengthen the wheel base on this chair to any extent and to include a position which will allow the chair to ascend and descend the stair flights while maintaining the seat in proper seating position. The revolution of these parts is easily accomplished by a person sitting in the chair such that he may position the chair without aid.

Arms 18 for supporting and lifting the rear of the wheel-chair above the bottom steps of a stair are pivotally attached to the stems 15 so that they will revolve in the aforementioned parallel planes. When the stems 15 are in a generally straight down position the arms 18 extend to the rear. The operation of the arm 18 is best seen in a comparison of the schematics of FIGS. 6 and 7. FIG. 6 for example shows the chair entering a flight of stairs with the rear Wheel 16 contacting the bottom riser. By rotating the wheel 16 and arm 18 the arm contacts an upper step and draws the chair inwardly while lifting the wheel 16 and further revolution will draw the chair inwardly until the frame 1 rests on a stair at which time the wheel 16 is free for further rotation about pivot 9 to contact a stair upwardly therefrom as best illustrated in FIG. 8 at which time the frame 1 will be lifted off of the stair. The angle of extension may be adjusted with the screws 19 and the length of the arms may be adjusted with the threads 20. Hinges 21 may be provided so that the arms 18 may be pushed out of the way, when not in use.

At one point, on entering or leaving the bottom of a stairs the main frame 1 will rest on a lower step; otherwise, the revolving rear wheel mechanism always supports the rear of the chair. This revolving mechanism provides means for entering or leaving a flight of stairs, for adjusting the chair to traverse stairs of different pitches, and for lengthening the wheel base for added stability or comfort.

Continuing with FIGURES 1 and 2: Numbers 22 are wheel-chair supporting arms that extend high above the chair and are provided with pivots 23' near the upper ends. The arms 22 are removable for transporting. The

pivots 23 are located so that the loaded wheel-chair would swing in a generally normal or level position if it were suspended freely from them. Connected to these pivots are combined mechanisms for lifting the wheelchair and for checking the descent.

FIGURE 12 is a side cross sectional view of the combined, compound hydraulic lift and check mechanism. FIGURE 13 is a top cross sectional view at 13-13. A cylinder 24 having the lower end closed and fitted with a stair contacting foot 25 is fitted with a piston 26 and liquid seal 27. The piston 26 terminates the lower end of a second and smaller diameter cylinder 28. Two holes are drilled through the piston 26 the first 29 is very small to greatly restrict the flow of liquid for checking wheel-chair descent; the second hole 30 is larger to permit rapid ascent and is automatically closed by the check valve 31 to check descent. The smaller cylinder 28 is fitted with a piston 32 a and liquid seal 33. A piston rod 34 connects the piston 32 with the aforesaid pivot 23. A transverse weight transfer bar 35 rigidly connects the upper end of one cylinder 28 with the upper end of the other cylinder 28. The bar 35 is removable for transporting and each supporting arm 22 together with a complete hydraulic lifter is removable from the chair, for transporting.

A brake system is provided for each of the front wheels 36 and is mounted respectively in braking position to each of the wheels 36 to check only the forward rotation thereof while permitting rearward rotation thereof. In the form shown particularly in the enlarged views of FIGS. 14 and 15 the brakes comprise L shaped members connected at the junction of the arms thereof with a transverse shaft 38 which extends and is rotatably mounted between both front wheel supports 6. The brake 37 is formed on the end of the short arm of the L and the L is so positioned that the brake will permit rotation in one direction but will prevent rotation in the other. Intermediate the pivot point 38 and the operating handle 39 in the long arm of the L a sprocket 40 is mounted on each of the brake systems and the sprockets 40 are connected through a shaft 41 such that the sprockets on each brake arm 3-9 will rotate in unison. A drive chain 42 is provided to be normally driven by the wheels 36 and when the brake lever 39 is in braking position the sprockets 4t engage the chain and as either wheel 36 is now rotated the motion will be transferred through the shaft 41 to both the sprockets 40 such that the wheels 36 must turn in unison.

To lift the wheel-chair from one step to the next: The feet 25 are placed on the first step above the one that the wheels 36 rest on, the brakes 37 are set to prevent forward turning of the drive wheels 36, the occupant of the chair transfers a major part of his weight from the chair to the bar 35 in a simulated chinning action. This action transfers weight from the chair to a step and also urges the pistons 26 down. Forcing the pistons 26 down, in turn forces the pistons 32 up and thereby lifts the wheel-chair.

To lower the wheel-chair: The feet 25 are placed beside the wheels 36, the brakes 37 are released permitting the wheels 36 to turn forward and the hydraulic mechanism now sets to check the descent.

The springs 43 set to lift the feet 25 from the one step to the next, preparatory to ascending a step. The tension of the springs 43 is released with the lever 44 to permit the feet 25 to drop from one step to the next, for descending stairs.

The operation of the chair is schematically illustrated in FIGS. 3 through 11. FIG. 3 is in the position for operating on a level floor with a dotted position showing a lengthened wheel base for the chair.

FIGS. 6 and 7 illustrate the chair being readied for entering a flight of stairs and as hereinbefore discussed the rear wheel 16 and arm 18 aid in bringing the chair in position for climbing and then are revolved into the position further shown in FIG. 8 to establish the spaced wheels supports on which the chair rests as it climbs the stairs. FIG. 8 further shows the lifting mechanism in position on the lower step to raise the chair and when the user provides the chinning action to lift his weight and lift the chair the next following position is illustrated in FIG. 4 which shows the front wheels 36 lifted off the ground and moved upwardly. In FIG. is the next sequential illustration and FIG. 9 follows FIG. 5 to show that when the bottom wheel has cleared the step 36 the chair is clear to pivot about pivot 23 and therefore will swing into and onto the step. FIGS. and 11 illustrate the position and use of the rear wheel 16 assembly upon reaching the top of a flight of stairs in order to keep the user in an upright position and to again bring the chair to an upright position when the upper floor is reached.

Though these schematic illustrations have been described for ascending a flight of stairs a reversal starting at FIG. 11 will accommodate descending a flight of stairs.

The operation of this wheel-chair requires some athletic ability as the occupant must lift about two-thirds of his weight a relative distance of about 1 /2 feet for each 9" lift. The percentage of his weight which a person must lift of course may be varied through changes in the relative size of the piston members. The chair actually will find its greatest use with handicapped people who still are sufliciently strong to support a portion of their weight but other devices could be incorporated to aid a weaker person to lift his weight.

FIGURES 14 and 15 show a wheel-chair that can be geared to require very little strength to operate and that can be stopped safe very frequently for rest periods.

FIG. 14 is :a side view and FIG. 15 is a top view of a wheel-chair provided with crank driven bars for ascending and descending stairs.

The mechanism for entering or leaving a flight of stairs is the same as before and parts number 1 through 21 are as previously described.

Cams 45 are placed on shaft 9 and are connected through bars 44 to shift the wheel supporting arms 46 between a generally straight down, normal running position, and a stair climbing position, as shown. The bars 44 also carry lugs 47 for operatnig clutches 48.

Normally the front drive wheels 49 are free to turn independent of each other. In the stair climbing position, as shown, the clutches 48 engage the chain drive mechanisms 50 so that the wheels 49 become the means for turning the crank shaft 51 in either direction.

51 is a transverse shaft, bearing mounted near the front edge of the foot rest 7. It is provided with chain driven sprockets near each end and cranks 52 at each end. The cranks 52 must be arranged to throw in unison and they may be mutliple throw. Triple throw cranks set apart are shown.

Stair traversing bars 53 are bearing connected to each crank and they extend to the rear of the chair and up from the said bearings. The upper end of each bar 53 is provided with an offset extension 54 to provide stair clearance for the supporting bar 55. This offset construction permits the bars to move in opposite directions, relative to each other, without seriously objectionable friction contact with a stair step.

The bar 55 is fixed under the upper ends of the main frame 1 and passes across and under the extensions 54 to carry the upper ends of the traversing bars'53 without interference with the reciprocation of the bars 53.

A transverse bar 56 is mounted at the upper rear ends of the main frame llto support a roller 57 over each extension bar 54. The rollers 57 are for supporting part of the wheel-chair weight as it is moved over active stair traversing bars.

Each of the bars 53 is provided with a leg 58 that extends downwardly from the lower front end thereof.

Each leg 58 is provided with a resilient foot and they are used for lifting and lowering the wheel-chair and also for walking short horizontal distances, which is required for moving the chair toward or away from the bottom of stairs and for traversing unusually deep stair steps.

Each bar 53 is provided with additional legs 59 that are parallel with and equally spaced above and to the rear of legs 58. The legs 59 are used only for ascending and descending stairs and are otherwise similar to the legs 58.

The method of entering or leaving a stairs is the same as previously described, however, the legs 58 provide an additional means for moving the wheel-chair toward or away from the lower steps.

It will now be understood that the wheel-chair is to be backed upstairs and run forward to descend stairs. And that, while entering or leaving a stairs, the crank 12 must be turned at frequent intervals to adjust the rotative position of the rear wheel stems 15, so that the chair will be supported in a reasonably level position.

After the wheel-chair has been maneuvered onto a stairs it can be made to ascend or descend by turning the drive wheels 49 or by permitting them to turn. Note that when more than two of the feet 59 or 58 are in contact with steps, the crank shaft will be near a dead center at a stop same position, and that even in descending stairs the wheels 49 will have to be manually turned to lift the wheelchair over these dead centers, unless the wheels 49 are permitted to turn fast enough so that the momentum of them will carry over the said dead centers.

The mechanism that has been described is all adaptable to be power driven. Simple single acting power driven hydraulic jacks would replace the compound acting lifters, that are shown in the drawings, FIGURES 1 through 13. Power driven jacks would lift, and check the descent of, the high pivots 23 as previously described.

While the provision of a self-contained unit is a stated object, of my invention, it is also recognized that a remote source of power may be tapped to activate a power unit added to the wheel-chair.

A change in the source of motive power, or in the intermediate means for transmitting power, or in the form of, details, of arrangement of, or proportions of the various parts will not constitute a departure from the scope of my invention.

What I claim is:

1. A wheel chair for ascending and descending stair flights including:

(a) a chair support frame;

(b) a first pair of wheel members mounted for rotation on one end of said frame;

() a pair of rotatably mounted support stems on the other end of said frame;

(d) a second pair of wheel members rotatably mounted on said support stems;

(e) means for rotating said wheel support stems to adjust the wheel base length of a chair such that a sitting portion of a chair may be maintained in proper sitting position when the chair is placed on a stair flight;

(f) a pair of piston units pivotally mounted on a portion of the farme for oscillatory movement in a vertical plane adjacent the sides of said frame having a stair contacting portion on the bottom end thereof for contacting a stair;

(g) means for applying pressure to said piston for lifting at least a portion of the chair whereby at least said portion of the chair may be lifted upwardly and will pivot about said piston means to elevate the same to the next succeeding step,

2. The structure set forth in claim 1 wherein said piston means comprise a compound piston arrangement wherein depression of the separating portion of the piston will allow fluid to pass upward into a second portion of the piston to apply the lifting force to the chair.

3. The structure set forth in claim 2 wherein retraction means are provided on said piston to raise the stair contacting portion thereof to facilitate placing the same on the next stair.

4. The structure set forth in claim 1 wherein a support bar is provided on said wheel stem and extends rearwardly therefrom to contact a stair when the chair is in entering or leaving position at the bottom of a stair flight to support the chair while the wheel base is being lengthened to accommodate the slope of the stairs.

5. The structure set forth in claim 1 and one way brake means arranged in position to be applied to said first set of wheels when the chair is in stair climbing position said brake arranged to permit rotation of said wheel in one direction.

6. The structure set forth in claim 5 and wheel locking means cooperating with said brake means whereby said first set of wheels will rotate only in unison.

References Cited by the Examiner UNITED STATES PATENTS 468,022 2/ 1892 Bray 280-528 2,701,005 2/1955 Bennett et al 2805.3 2,931,449 4/1960 King -8 3,053,546 9/1962 Muirhead 2805.3 3,104,112 9/1963 Crail 280-52 FOREIGN PATENTS 1,363,987 5/1964 France.

LEO FRIAGLIA, Primary Examiner. 

1. A WHEEL CHAIR FOR ASCENDING AND DESCENDING STAIR FLIGHTS INCLUDING: (A) A CHAIR SUPPORT FRAME; (B) A FIRST PAIR OF WHEEL MEMBERS MOUNTED FOR ROTATION ON ONE END OF SAID FRAME; (C) A PAIR OF ROTATABLY MOUNTED SUPPORT STEMS ON THE OTHER END OF SAID FRAME; (D) A SECOND PAIR OF WHEEL MEMBERS ROTATABLY MOUNTED ON SAID SUPPORT STEMS; (E) MEANS FOR ROTATING SAID WHEEL SUPPORT STEMS TO ADJUST THE WHEEL BASE LENGTH OF A CHAIR SUCH THAT A SITTING PORTION OF A CHAIR MAY BE MAINTAINED IN PROPER SITTING POSITION WHEN THE CHAIR IS PLACED ON A STAIR FLIGHT; (F) A PAIR OF PISTON UNITS PIVOTALLY MOUNTED ON A PORTION OF THE FARME FOR OSCILLATORY MOVEMENT IN A VERTICAL PLANE ADJACENT THE SIDES OF SAID FRAME HAVING A STAIR CONTACTING PORTION ON THE BOTTOM END THEREOF FOR CONTACTING A STAIR; (G) MEANS FOR APPLYING PRESSURE TO SAID PISTON FOR LIFTING AT LEAST A PORTION OF THE CHAIR WHEREBY AT LEAST SAID PORTION OF THE CHAIR MAY BE LIFTED UPWARDLY AND WILL PIVOT ABOUT SAID PISTON MEANS TO ELEVATE THE SAME TO THE NEXT SUCCEEDING STEP. 